Figure 7.
Mba1 can function in the absence of Oxa1. (A) Translation reactions in wild-type, Δoxa1, or Δimp1 mitochondria were incubated with the cleavable cross-linker DSP and analyzed by immunoprecipitation as described in the legend to Fig. 3 B. mCox2, mature Cox2. (B) 35S-labeled Oxa1 precursor was imported for 15 min at 25°C into wild-type, Δoxa1, and Δoxa1Mba1↑ mitochondria. The samples were divided into three parts. Mitochondria (M) were then either mock treated, treated with proteinase K (PK), or converted to mitoplasts (MP) and proteinase K treated. Lane 1 shows 10% of the preprotein used per reaction. (C) The ratio of protease-accessible Oxa1 to total imported Oxa1 was quantified from four independent experiments and depicted in the diagram. Error bars show the standard deviation (n = 4).